diff --git a/src/Oms.Application/Dtos/Orders/ItfxCreateOrderOneBody.cs b/src/Oms.Application/Dtos/Orders/ItfxCreateOrderOneBody.cs
new file mode 100644
index 0000000..cd36ea9
--- /dev/null
+++ b/src/Oms.Application/Dtos/Orders/ItfxCreateOrderOneBody.cs
@@ -0,0 +1,57 @@
+namespace Oms.Application.Dtos.Orders;
+
+/// <summary>
+/// itfx createOrderOne（ForwardWithSubscribe）标准请求体。
+/// 仅包含下游接口字段，不含 OMS 内部扩展参数。
+/// </summary>
+public class ItfxCreateOrderOneBody
+{
+    public string? ClientNo { get; set; }
+
+    public string? TrackNo { get; set; }
+
+    public string? ServiceNo { get; set; }
+
+    /// <summary>
+    /// 下游产品代码：取服务渠道「预报渠道 code」（ForecastCode）。
+    /// </summary>
+    public string? ProductCode { get; set; }
+
+    public string? CargoAttribute { get; set; }
+
+    public int? WarehouseId { get; set; }
+
+    public int? CustomerId { get; set; }
+
+    public decimal? Length { get; set; }
+
+    public decimal? Width { get; set; }
+
+    public decimal? Height { get; set; }
+
+    public decimal? ActualWeight { get; set; }
+
+    public decimal? VolumetricWeight { get; set; }
+
+    public decimal? ChargeableWeight { get; set; }
+
+    public decimal? Cubic { get; set; }
+
+    public bool IsCod { get; set; }
+
+    public string? CodCurrency { get; set; }
+
+    public string? CodSum { get; set; }
+
+    public string? DeclaredCurrency { get; set; }
+
+    public string? DeclaredSum { get; set; }
+
+    public string? Quantity { get; set; }
+
+    public OrderParcelReceiverInput? Receiver { get; set; }
+
+    public OrderParcelSenderInput? Sender { get; set; }
+
+    public List<OrderParcelItemInput> Items { get; set; } = [];
+}
diff --git a/src/Oms.Application/Dtos/Orders/OrderDownstreamForwardDtos.cs b/src/Oms.Application/Dtos/Orders/OrderDownstreamForwardDtos.cs
index 472212e..c69e78c 100644
--- a/src/Oms.Application/Dtos/Orders/OrderDownstreamForwardDtos.cs
+++ b/src/Oms.Application/Dtos/Orders/OrderDownstreamForwardDtos.cs
@@ -13,7 +13,7 @@ public class OrderDownstreamCreateOneBodyOutput
 
     public string SupplierCode { get; set; } = string.Empty;
 
-    public OrderParcelCreateInput Body { get; set; } = new();
+    public ItfxCreateOrderOneBody Body { get; set; } = new();
 }
 
 /// <summary>
diff --git a/src/Oms.Application/Integrations/Itfx/ItfxForwardClient.cs b/src/Oms.Application/Integrations/Itfx/ItfxForwardClient.cs
index 4ab5564..c61ad95 100644
--- a/src/Oms.Application/Integrations/Itfx/ItfxForwardClient.cs
+++ b/src/Oms.Application/Integrations/Itfx/ItfxForwardClient.cs
@@ -17,6 +17,7 @@ internal sealed class ItfxForwardClient(
     private static readonly JsonSerializerOptions JsonOptions = new()
     {
         PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull,
         WriteIndented = true
     };
 
diff --git a/src/Oms.Application/Services/Orders/Batch/OrderBatchActionExecutor.cs b/src/Oms.Application/Services/Orders/Batch/OrderBatchActionExecutor.cs
index 77113cc..a88f537 100644
--- a/src/Oms.Application/Services/Orders/Batch/OrderBatchActionExecutor.cs
+++ b/src/Oms.Application/Services/Orders/Batch/OrderBatchActionExecutor.cs
@@ -7,6 +7,7 @@ using Oms.Application.Integrations.SmallBagTrack;
 using Oms.Application.Messaging;
 using Oms.Application.Shared;
 using Oms.Application.Storage;
+using Oms.Domain.ChannelsAggregate.Repositories;
 using Oms.Domain.OrdersAggregate.Consts;
 using Oms.Domain.OrdersAggregate.Entities;
 using Oms.Domain.OrdersAggregate.Repositories;
@@ -17,6 +18,7 @@ namespace Oms.Application.Services.Orders.Batch;
 public sealed class OrderBatchActionExecutor(
     IOrderRepository orderRepository,
     ICountryRepository countryRepository,
+    IServiceChannelRepository serviceChannelRepository,
     IFileStorage fileStorage,
     ISmallBagTrackOrderClient smallBagTrackOrderClient,
     ISmallBagTrackUpsertRequestBuilder smallBagTrackUpsertRequestBuilder,
@@ -145,12 +147,12 @@ public sealed class OrderBatchActionExecutor(
 
         try
         {
-            OrderParcelCreateInput body;
+            ItfxCreateOrderOneBody body;
             Order order;
 
             if (!string.IsNullOrWhiteSpace(message.PayloadJson))
             {
-                body = JsonConvert.DeserializeObject<OrderParcelCreateInput>(message.PayloadJson!)
+                body = JsonConvert.DeserializeObject<ItfxCreateOrderOneBody>(message.PayloadJson!)
                     ?? throw new BusinessException("下游预报消息体无效");
 
                 // 凭证解析仍需订单上的渠道/下游绑定字段；有 payload 时只查主表一次
@@ -178,6 +180,7 @@ public sealed class OrderBatchActionExecutor(
                     bundle.Declarations,
                     bundle.Weights,
                     countryRepository,
+                    serviceChannelRepository,
                     fileStorage,
                     cancellationToken);
             }
diff --git a/src/Oms.Application/Services/Orders/Batch/OrderBatchJobCoordinator.cs b/src/Oms.Application/Services/Orders/Batch/OrderBatchJobCoordinator.cs
index b7df2fa..fed05fe 100644
--- a/src/Oms.Application/Services/Orders/Batch/OrderBatchJobCoordinator.cs
+++ b/src/Oms.Application/Services/Orders/Batch/OrderBatchJobCoordinator.cs
@@ -9,6 +9,7 @@ using Oms.Application.Integrations.SmallBagTrack;
 using Oms.Application.Messaging;
 using Oms.Application.Shared;
 using Oms.Application.Storage;
+using Oms.Domain.ChannelsAggregate.Repositories;
 using Oms.Domain.OrdersAggregate.Consts;
 using System.Linq.Expressions;
 using Oms.Domain.OrdersAggregate.Entities;
@@ -24,6 +25,7 @@ public sealed class OrderBatchJobCoordinator(
     IOrderBatchJobRepository batchJobRepository,
     IOrderRepository orderRepository,
     ICountryRepository countryRepository,
+    IServiceChannelRepository serviceChannelRepository,
     IFileStorage fileStorage,
     IOrderBatchJobPublisher publisher,
     OrderBatchJobProcessor batchJobProcessor,
@@ -651,6 +653,7 @@ public sealed class OrderBatchJobCoordinator(
                 bundle.Declarations,
                 bundle.Weights,
                 countryRepository,
+                serviceChannelRepository,
                 fileStorage,
                 cancellationToken);
             result[orderId] = JsonConvert.SerializeObject(body);
diff --git a/src/Oms.Application/Services/Orders/OrderService.DownstreamForward.cs b/src/Oms.Application/Services/Orders/OrderService.DownstreamForward.cs
index 3c90eda..b8eb919 100644
--- a/src/Oms.Application/Services/Orders/OrderService.DownstreamForward.cs
+++ b/src/Oms.Application/Services/Orders/OrderService.DownstreamForward.cs
@@ -82,7 +82,7 @@ public partial class OrderService
         };
     }
 
-    private async Task<(Domain.OrdersAggregate.Entities.Order order, OrderParcelCreateInput body)> LoadDownstreamCreateOneContextAsync(
+    private async Task<(Domain.OrdersAggregate.Entities.Order order, ItfxCreateOrderOneBody body)> LoadDownstreamCreateOneContextAsync(
         int orderId)
     {
         var bundles = await OrderRepository.GetDownstreamCreateOneBundlesAsync([orderId]);
@@ -98,6 +98,7 @@ public partial class OrderService
             bundle.Declarations,
             bundle.Weights,
             CountryRepository,
+            ServiceChannelRepository,
             FileStorage);
 
         return (bundle.Order, body);
diff --git a/src/Oms.Application/Shared/OrderDownstreamCreateOneBodyBuilder.cs b/src/Oms.Application/Shared/OrderDownstreamCreateOneBodyBuilder.cs
index fadb54e..aa8c17a 100644
--- a/src/Oms.Application/Shared/OrderDownstreamCreateOneBodyBuilder.cs
+++ b/src/Oms.Application/Shared/OrderDownstreamCreateOneBodyBuilder.cs
@@ -1,5 +1,6 @@
 using Oms.Application.Dtos.Orders;
 using Oms.Application.Storage;
+using Oms.Domain.ChannelsAggregate.Repositories;
 using Oms.Domain.OrdersAggregate.Consts;
 using Oms.Domain.OrdersAggregate.Entities;
 using Oms.Domain.SystemAggregate.Repositories;
@@ -7,17 +8,18 @@ using Oms.Domain.SystemAggregate.Repositories;
 namespace Oms.Application.Shared;
 
 /// <summary>
-/// 从订单表及关联子表组装 createOrderOne 标准请求体。
+/// 从订单表及关联子表组装 itfx createOrderOne 标准请求体。
 /// </summary>
 public static class OrderDownstreamCreateOneBodyBuilder
 {
-    public static async Task<OrderParcelCreateInput> BuildAsync(
+    public static async Task<ItfxCreateOrderOneBody> BuildAsync(
         Order order,
         OrderSender? sender,
         OrderRecipient? recipient,
         IReadOnlyList<OrderDeclaration> declarations,
         IReadOnlyList<OrderWeight> weights,
         ICountryRepository countryRepository,
+        IServiceChannelRepository serviceChannelRepository,
         IFileStorage? fileStorage = null,
         CancellationToken cancellationToken = default)
     {
@@ -41,16 +43,18 @@ public static class OrderDownstreamCreateOneBodyBuilder
                             string.Equals(x.Type, OrderWeightTypeCodes.Forecast, StringComparison.OrdinalIgnoreCase))
                        ?? weights.FirstOrDefault();
 
-        return new OrderParcelCreateInput
+        var productCode = await ResolveForecastProductCodeAsync(
+            order,
+            serviceChannelRepository,
+            cancellationToken);
+
+        return new ItfxCreateOrderOneBody
         {
-            RequestId = order.RequestId,
             ClientNo = order.ClientNo,
             TrackNo = order.TrackNo,
             ServiceNo = order.ServiceNo,
-            ProductCode = order.ProductCode,
-            ChannelCode = order.ChannelCode,
+            ProductCode = productCode,
             CargoAttribute = order.CargoAttribute,
-            ExportCustomsMode = order.ExportCustomsMode,
             WarehouseId = order.WarehouseId,
             CustomerId = order.CustomerId,
             Length = forecast?.Length,
@@ -62,16 +66,45 @@ public static class OrderDownstreamCreateOneBodyBuilder
             Cubic = forecast?.Cubic,
             IsCod = order.IsCod > 0,
             CodCurrency = order.CodCurrency,
-            CodSum = order.CodSum,
+            CodSum = FormatDecimal(order.CodSum),
             DeclaredCurrency = order.DeclaredCurrency,
-            DeclaredSum = order.DeclaredSum,
-            Quantity = order.Quantity,
+            DeclaredSum = FormatDecimal(order.DeclaredSum),
+            Quantity = order.Quantity?.ToString(),
             Receiver = MapReceiver(recipient, order.ConsigneeCountry, idToCode),
             Sender = MapSender(sender, idToCode),
             Items = declarations.Select(x => MapItem(x, fileStorage)).ToList()
         };
     }
 
+    /// <summary>
+    /// createOrderOne.productCode = 渠道「预报渠道 code」：
+    /// 优先订单固化的 ChannelForecastCode，否则 live 查 t_service_channel.ForecastCode。
+    /// </summary>
+    private static async Task<string?> ResolveForecastProductCodeAsync(
+        Order order,
+        IServiceChannelRepository serviceChannelRepository,
+        CancellationToken cancellationToken)
+    {
+        var snapshotted = order.ChannelForecastCode?.Trim();
+        if (!string.IsNullOrWhiteSpace(snapshotted))
+        {
+            return snapshotted;
+        }
+
+        var channelCode = order.ChannelCode?.Trim();
+        if (string.IsNullOrWhiteSpace(channelCode))
+        {
+            return null;
+        }
+
+        var channel = await serviceChannelRepository.GetByChannelCodeAsync(channelCode, cancellationToken);
+        var forecastCode = channel?.ForecastCode?.Trim();
+        return string.IsNullOrWhiteSpace(forecastCode) ? null : forecastCode;
+    }
+
+    private static string? FormatDecimal(decimal? value) =>
+        value.HasValue ? value.Value.ToString(System.Globalization.CultureInfo.InvariantCulture) : null;
+
     private static string? ResolveCountryIso(int? countryId, string? orderConsigneeCountry, IReadOnlyDictionary<int, string> idToCode)
     {
         if (!string.IsNullOrWhiteSpace(orderConsigneeCountry))
@@ -83,9 +116,9 @@ public static class OrderDownstreamCreateOneBodyBuilder
             }
         }
 
-        if (countryId is > 0 && idToCode.TryGetValue(countryId.Value, out var code) && !string.IsNullOrWhiteSpace(code))
+        if (countryId is > 0 && idToCode.TryGetValue(countryId.Value, out var iso) && !string.IsNullOrWhiteSpace(iso))
         {
-            return code.Trim().ToUpperInvariant();
+            return iso.Trim().ToUpperInvariant();
         }
 
         return null;
diff --git a/src/Oms.Tests/OrderBatchJobCoordinatorGovernanceTests.cs b/src/Oms.Tests/OrderBatchJobCoordinatorGovernanceTests.cs
index aa50039..444ade9 100644
--- a/src/Oms.Tests/OrderBatchJobCoordinatorGovernanceTests.cs
+++ b/src/Oms.Tests/OrderBatchJobCoordinatorGovernanceTests.cs
@@ -7,6 +7,7 @@ using Oms.Application.Dtos.Orders;
 using Oms.Application.Messaging;
 using Oms.Application.Services.Orders.Batch;
 using Oms.Application.Storage;
+using Oms.Domain.ChannelsAggregate.Repositories;
 using Oms.Domain.OrdersAggregate.Consts;
 using Oms.Domain.OrdersAggregate.Entities;
 using Oms.Domain.OrdersAggregate.Repositories;
@@ -19,6 +20,7 @@ public class OrderBatchJobCoordinatorGovernanceTests
     private readonly Mock<IOrderBatchJobRepository> _batchJobRepository = new(MockBehavior.Strict);
     private readonly Mock<IOrderRepository> _orderRepository = new(MockBehavior.Loose);
     private readonly Mock<ICountryRepository> _countryRepository = new(MockBehavior.Loose);
+    private readonly Mock<IServiceChannelRepository> _serviceChannelRepository = new(MockBehavior.Loose);
     private readonly Mock<IFileStorage> _fileStorage = new(MockBehavior.Loose);
     private readonly Mock<IOrderBatchJobPublisher> _publisher = new(MockBehavior.Strict);
     private readonly OrderBatchJobCoordinator _coordinator;
@@ -38,6 +40,7 @@ public class OrderBatchJobCoordinatorGovernanceTests
             _batchJobRepository.Object,
             _orderRepository.Object,
             _countryRepository.Object,
+            _serviceChannelRepository.Object,
             _fileStorage.Object,
             _publisher.Object,
             processor,